E. coli purine nucleoside phosphorylase Substitution; Enzyme kinetics;

1: 80 percent / NaH / acetonitrile / 4 h / 20 °C 2: 88 percent / NaOCH3 / methanol / 3 h / 20 °C View Scheme

1: 92 percent / (Ph3P)4Pd / tetrahydrofuran / 4.5 h / 55 °C 2: 84 percent / 1 M MeONa / methanol / 2 h / 20 °C View Scheme

1: NaH / acetonitrile 2: 87 percent / MeONa / methanol View Scheme

1: 88 percent / DMAP / acetonitrile / 2 h 2: 98 percent / AIBN, (nBu)3SnH / 2 h / 75 °C 3: 98 percent / NH4F / methanol / 16 h / 40 °C View Scheme

1: 100 percent / NH3/MeOH / 3.5 h / Ambient temperature 2: 88 percent / DMAP / acetonitrile / 2 h 3: 98 percent / AIBN, (nBu)3SnH / 2 h / 75 °C 4: 98 percent / NH4F / methanol / 16 h / 40 °C View Scheme

1: 98 percent / AIBN, (nBu)3SnH / 2 h / 75 °C 2: 98 percent / NH4F / methanol / 16 h / 40 °C View Scheme

T=37°C; 7 h; alginate gel-entrapped cells of auxotrophic thymine-dependent strain of E. coli, ammonium acetate buffer, pH 5.7; donor activity of sugar-modified uracil and thymine nucleosides in transglycosylation reaction with 6-methylpurine and hypoxanthine; Product distribution;